The present invention relates to material handling and relates in particular to a process for transferring finely divided solids such as coal from a receptacle under atmospheric pressure into a system or reactor under high pressure, i.e., of the order of 500 to 10,000 psi.
Therefore, a special feature of the invention is the provision of the process which is operable to introduce dry solids into a high pressure reaction system.
A further feature of the invention is the provision of a process of the type described in which a solids carrier is utilized and the carrier is readily separable from the solids.
A further feature of the invention is the use of a dense carrier having a specific gravity, higher than the specific gravity of the solids, so that the solids will readily float on the carrier.
A further feature of the invention is the use of a carrier which when in the fluid condition is immiscible relative to finely divided solids.
Prior art devices and processes utilized to introduce solids held under atmospheric pressure into high pressure systems or high pressure reactors usually require complicated air locks or pressurized hoppers to effect the transfer.
Frequently, the size and capital cost of such air locks limit the pressure levels at which material transfers can be made. For example, if it is intended to introduce material normally under atmospheric pressure into a system at 5,000 psi, a series of air locks are usually required, each stepping down in volume and each incrementally increasing in pressure level as the material is moved sequentially from the larger air lock or hopper to the next smaller air lock and ultimately into the reaction system.
Furthermore, in prior art material handling processes, series air locks used to reach high pressure levels have to be stepped down in volume as pressure levels are stepped up in order to insure containment of pressure at the higher levels.
In contrast, the process of the present invention contemplates a single unit of small size, capable of making a material transfer from atmospheric pressure to a receptacle under pressures as high as 10,000 psi in a single step.
In the present process, if a high feed rate is desired, it is merely necessary to provide a plurality of process units, each feeding the same system or reactor.